Abstract
The City of Grapevine, Texas is in North Central Texas and serves a population of nearly 54,000. Its' destination status could cause population to triple on any given week or weekend. In 1983, the City undertook efforts to re-construct the only raw water line for the city's single water treatment plant. City staff decided in 2020 that an inspection of approximately 1 mile of twenty (20) inch bar-wrapped cylinder concrete pipe should be performed so that a condition assessment consisting of remaining useful life and other analyses could be conducted. When it was decided that an inspection was necessary, a comparison of the available technologies for in-line inspection of pressure pipe was initiated. Since the City of Grapevine had experience with near field transmission inspection platforms, this is where the comparison began. Near field transmission and remote field transmission have been the technologies most utilized for over 20 years. While each of these technologies have contributed greatly to the water and wastewater community, the data produced by each technology is very specific in scope, limited to ferrous pipe, and can be inconsistent at times. Moreover, the transport mechanisms utilized to deploy these technologies introduce another complex variable. Ultimately, the City of Grapevine came to the temporary conclusion that they would utilize the most prominent provider in the market since they had experience with the near field transmission platform and its associated deliverables. Sounding in conjunction with visual inspection have been utilized by owners since the 1980's as a means of inspecting pipe. However, this requires confined space entry, is subjective, and is limited in diameter. The advent of Ultrasonic Testing (UT) in an in-line inspection technology for pressure pipe has eliminated these limitations while producing more data that can be utilized for condition assessment of water transmission mains and force mains. The reach of this technology is also expanded by the existence of multiple deployment options. This technology was only available in the Netherlands until recently. When presented with the opportunity to utilize the new in-line inspection platform with ultrasonic testing capabilities to inspect their pressurized pipe, the City of Grapevine re-evaluated their selection of a near-field inspection platform. The primary reason City Staff elected the UT based technology was the availability of more data, absolute anomaly location, joint defect data, and to a lesser extent, cost. This technology has the capabilities of inspecting any material type, both ferrous and non-ferrous providing wall thickness, joint condition (angular displacement/ gap width, sub-meter XYZ mapping, leaks, and gas pockets in a single inspection. The decision-making process that the City of Grapevine undertook to determine the best course of action for inspecting pressure pipe is not dissimilar from the process collections systems personnel and management must make when determining a course of action for inspecting pressure pipe. By understanding the primary technologies and deployment mechanisms that are most utilized for in-line inspection of pressure pipe, a better understanding of what to expect from each technology is gained. Near field, remote field, and ultrasonic testing platforms will be explored in depth to provide an understanding of how each technology works, is deployed, and what to expect from each deliverable. A presentation of the project itself is necessary and will provide familiarity with the ultrasonic tool its operational process and in depth look at the value of the deliverables since it has been used extensively in the Netherlands and most recently in the UK. Pre-planning, civil engineering, launch and retrieval, and the deliverable(s) will be presented to provide a full scope of this new innovative technology. By understanding all aspects of an inspection of a single pressurized raw water line in Grapevine, Texas, collections system personnel and management can prepare themselves for future, larger scale inspections by being equipped with knowledge about the most widely used platforms, advantages, and disadvantages of each, what to expect from a civil engineering standpoint, and from a deliverable. This information empowers collection system operators and owners to make informed decisions about inspecting and assessing the condition of their critical infrastructure and better manage their pressurized assets.
This paper was presented at the WEF Collection Systems Conference, June 27-30, 2023.
Author(s)C. McDowell1;
Author affiliation(s)CPM Pipelines1;
SourceProceedings of the Water Environment Federation
Document typeConference Paper
Print publication date Jun 2023
DOI10.2175/193864718825158901
Volume / Issue
Content sourceCollections
Copyright2023
Word count25